Always nice to resurrect the old hi-if- you could dig out the technics, add speakers of choice (loads on the bay, gumtree and FB) and then there ar some really good Bluetooth receivers that pair with your phone and turn the signal into something you can run into your old amplifier.
I’ve just added a Fio Bluetooth receiver on a recommendation from LGF (about 50 quid) and it is astoundingly good, especially if you run high quality output from Spotify. You can also get them much cheaper.